The invention relates to a roller bearing for linear movements.
Linear roller bearings of this and similar kinds are being employed in many fields of machinery and of automotive vehicle technology. By such roller bearings, constructional parts that are slideable relative to each other in longitudinal direction can be mounted against each other like bearings. In shaft arrangements the parts of which are slideable relative to each other telescopically in longitudinal direction, such a bearing must additionally transfer the torques applied to the shaft. Such telescopic shafts with variable length are used for example as steering shafts of steering columns in automotive vehicles. Thereby the position of a steering wheel in the vehicle can be adapted to the individual requirements of the operator. Since additionally the steering shaft transfers the steering torque from the steering wheel to the steering gear, the parts of the steering shaft must additionally be coupled with each other in a manner fixed against rotation. By means of one or more linear roller bearings arranged between the two parts of the shaft the axial sliding forces can be kept low and relatively constant along the entire sliding area.
FR 2 795 785 A1 discloses a similar arrangement wherein directly between at least one of the races of the two guide members and the roller members a plurality of individual elastic elements or spring means is arranged.
EP 1 070 865 A2 discloses a linear roller bearing for transmitting torques which is not provided with roller members arranged behind each other in a linear manner, but with ball rings provided between an inner and an outer profile element in a cage, wherein roller members movable in a first guide path are pre-biased by means of a spring metal sheet. The ball rings have load zones and zones free of load between the profile elements. Due to this arrangement with ball rings, the linear roller bearing is designed in a very expensive manner.
In EP 1 106 851 A1, the elastic element or spring means provided therein serves above all the purpose to balance manufacturing tolerances within a certain limit. For this purpose the spring means is arranged either between at least one race plate and a recess receiving this plate in a guide member formed as a sleeve or between a race plate and a corresponding recess in the guide member being formed as a guide rod. By the spring means, the roller members are pressed at least in radial direction into their respective positions or they are pre-biased in radial direction, but partially also biased in circumferential direction.